Image processing method and device

Abstract

A two-line sensor type image input and processing apparatus and method for accurately determining the current scan state, start of scanning and end of scanning events, as well as estimating scanning speed corresponding thereto, and for performing high precision distortion correction on the basis of these estimated scanning speeds. This image input and processing method or apparatus may comprise 1) overall speed judgment that judges the scanning speed based on feature data from the two sensors; 2) stop state judgment that judges whether or not the image input member is in a scan stop state with the input switch for facilitating image data input in the ON state; 3) pre/post stop state speed judgment that judges the scanning speed before and after the scan stop state based on the scan stop time judged by stop state judgment and the overall scanning speed judged by overall speed judgment; 4) scan start judgment that judges whether or not the image input member started scanning; 5) scan start speed judgment that judges the scanning speed at scan start; 6) scan end judgment that judges whether or not the image input member has ended scanning; 7) scan end speed judgment that judges the scanning speed at scan end; 8) ring buffer write end position updating that uses a ring buffer as the buffer for storing image data and updates the write end address in the ring buffer; and means for correcting images based on speed and start/stop information generated from these various speed judgment devices or processes.

What is claimed is: 
     
       1. An image acquisition and processing device, comprising: an image input member for acquiring character and graphical information from a document, said image input member comprising: a scan activation means for selectively activating and deactivating scanning operations within said image input member; and   spaced apart first and second sensors for reading the character and graphical information when illuminated by a light source and converting the read-in information into corresponding first and second image data streams in response to said scan activation means; and     an image processing member in communication with said image input member, said image processing member comprising: a buffer in communication with said image input member for receiving and storing the first and second image data streams;   an overall speed judgment device in communication with said buffer for extracting image features for the first and second image data streams, comparing the extracted features for the first and second image data streams and obtaining correlation and time-offset information therefrom, and generating overall scanning speed in response to the obtained correlation and time-offset information;   a stop state judgment device in communication with said buffer for detecting when said image input member is in a scan stop state with said scan activation means activating scan operations, and determining a scan stop time interval if the scan stop state is so detected;   a pre/post stop state speed judgment device in communication with said overall speed judgment and stop state judgment devices for generating scanning speeds immediately prior to and after the scan stop time interval when the scan stop state is detected based on the overall scanning speed generated by said overall speed judgment device; and   an image corrector in communication with said overall speed judgment device and said pre/post stop state speed judgment device for correcting scanning distortion present in one of the stored image data streams based on the scanning speeds generated by said pre/post stop state speed judgment and overall speed judgment devices.     
     
     
       2. The image acquisition and processing device of claim 1, wherein said stop state judgment device observes temporal changes in at least one of said image data streams and determines that said image input member is in the scan stop state when no temporal changes have been detected for at least a predetermined time period. 
     
     
       3. The image acquisition and processing device of claim 2, wherein the predetermined time period is based on the overall scanning speed prior to detection of the scan stop state. 
     
     
       4. The image acquisition and processing device of claim 2, wherein the predetermined time period is based on relative character size of images contained within said first and second image data streams. 
     
     
       5. The image acquisition and processing device of claim 2, wherein the predetermined time period is based on the overall scanning speed prior to detection of the scan stop state and relative character size of images contained within said first and second image data streams. 
     
     
       6. The image acquisition and processing device of claim 2, wherein the predetermined time period ranges from approximately 100 msec to 200 msec. 
     
     
       7. The image acquisition and processing device of claim 1, wherein said pre/post stop state speed judgment device estimates the scanning speed immediately prior to the scan stop state based on previously calculated overall scanning speeds generated by said overall speed judgment device and estimates the scanning speed immediately after the scan stop state based on the estimated scanning speed immediately prior to the scan stop state. 
     
     
       8. The image acquisition and processing device of claim 7, wherein said pre/post stop state speed judgment device continuously links the scanning speed immediately prior to the scan stop state to a scanning speed at the start of the scan stop time interval when the estimated scanning speed immediately prior to the scan stop state is less than zero, and discontinuously links the scanning speed immediately prior to the scan stop state to the scanning speed at the start of the scan stop time interval when the estimated scanning speed immediately prior to the scan stop state is greater than zero. 
     
     
       9. The image acquisition and processing device of claim 7, wherein said pre/post stop state speed judgment device continuously links the scanning speed immediately after the scan stop state to a scanning speed at the end of the scan stop time interval. 
     
     
       10. The image acquisition and processing device of claim 1, said image processing member further comprising: a scan start judgment device in communication with said buffer for detecting when said image input member has commenced scanning movement with said scan activation means activating scan operations, and generating a scan start event if scanning movement has been so detected; and   a scan start speed judgment device in communication with said scan start judgment device, said overall speed judgment device, and said image corrector for generating a scanning speed at the scan start event generated by said scan start judgment device; and   wherein said image corrector corrects scanning distortion present in one of the stored image data streams based on the scanning speeds generated by said pre/post stop state speed judgment, said scan start speed judgment and said overall speed judgment devices.   
     
     
       11. The image acquisition and processing device of claim 10, wherein said scan start judgment device observes temporal changes in the first and second image data streams and determines that a scan start event has occurred when there is a change in either image data stream. 
     
     
       12. The image acquisition and processing device of claim 11, wherein said scan start judgment device observes temporal changes in the first and second image data streams and determines that a scan start event has not occurred when a black region is perceived within a periphery of either sensor read area when a change has been detected within either of the image data streams. 
     
     
       13. The image acquisition and processing device of claim 11, wherein said scan start speed judgment device estimates a scanning speed at the scan start event based on an overall scanning speed calculated by said overall speed judgment device immediately after the scan start event and the input image prior to the scan start event. 
     
     
       14. The image acquisition and processing device of claim 13, wherein said scan start speed judgment devices assumes the scanning speed at the scan start event to be zero when a black region is perceived in the input image prior to the scan start event which does not extend to a periphery of either sensor read area. 
     
     
       15. The image acquisition and processing device of claim 13, wherein said scan start speed judgment device estimates the scanning speed at the scan start event based on an overall scanning speed calculated by said overall speed judgment device immediately after the scan start event when the input image prior to the scan start event is either entirely white or contains a black region extending to a periphery of either sensor read area. 
     
     
       16. The image acquisition and processing device of claim 15, wherein said scan start speed judgment device assumes the scanning speed at the scan start event to be zero when the estimated scanning speed at the scan start event is less than zero. 
     
     
       17. The image acquisition and processing device of claim 10, wherein said buffer comprises a ting buffer; and   wherein said image processing member further comprises a ring buffer write end position update device in communication with said scan start event device and said ring buffer for manipulating a write end address of said ring buffer when image data from either said first and second image data streams is deposited in said ring buffer and continually updating the write end address until a scan start event has been generated by said scan start judgment device.   
     
     
       18. The image acquisition and processing device of claim 1, said image processing member further comprising: a scan end judgment device in communication with said buffer for detecting when said image input member has terminated scanning movement with said scan activation means activating scan operations, and generating a scan end event if no scanning movement has been so detected; and   a scan end speed judgment device in communication with said scan end judgment device, said overall speed judgment device, and said image corrector for generating a scanning speed at the scan end event generated by said scan end judgment device; and   wherein said image corrector corrects scanning distortion present in one of the stored image data streams based on the scanning speeds generated by said pre/post stop state speed judgment, said scan end speed judgment, and said overall speed judgment devices.   
     
     
       19. The image acquisition and processing device of claim 18, wherein said scan end judgment device observes temporal changes in at least one of said image data streams and determines that said image input member is in the scan end state when no temporal changes have been detected for at least a second predetermined time period. 
     
     
       20. The image acquisition and processing device of claim 19, wherein said scan end judgment device determines the scan end event to occur at a time period immediately prior to detection of a black region at a periphery of either sensor read area, even when subsequent temporal changes to either image data stream has been detected. 
     
     
       21. The image acquisition and processing device of claim 18, wherein said scan start speed judgment device estimates a scanning speed at the scan end event based on an overall scanning speed calculated by said overall speed judgment device immediately before the scan start event and the input image after the scan end event. 
     
     
       22. The image acquisition and processing device of claim 21, wherein said scan end speed judgment devices assumes the scanning speed at the scan end event to be zero when a black region is perceived in the input image after the scan end event which does not extend to a periphery of either sensor read area. 
     
     
       23. The image acquisition and processing device of claim 21, wherein said scan end speed judgment device estimates the scanning speed at the scan end event based on an overall scanning speed calculated by said overall speed judgment device immediately before the scan end event when the input image after the scan end event is either entirely white or contains a black region extending to a periphery of either sensor read area. 
     
     
       24. The image acquisition and processing device of claim 23, wherein said scan end speed judgment device assumes the scanning speed at the scan end event to be zero when the estimated scanning speed at the scan end event is less than zero. 
     
     
       25. The image acquisition and processing device of claim 10, said image processing member further comprising: a scan end judgment device in communication with said buffer for detecting when said image input member has terminated scanning movement with said scan activation means activating scan operations, and generating a scan end event if no scanning movement has been so detected; and   a scan end speed judgment device in communication with said scan end judgment device, said overall speed judgment device, and said image corrector for generating a scanning speed at the scan end event generated by said scan end judgment device; and   wherein said image corrector corrects scanning distortion present in one of the stored image data streams based on the scanning speeds generated by said pre/post stop state speed judgment, said scan end speed judgment, and said overall speed judgment devices.   
     
     
       26. The image acquisition and processing device of claim 25 wherein said scan end judgment device observes temporal changes in at least one of said image data streams and determines that said image input member is in the scan end state when no temporal changes have been detected for at least a second predetermined time period. 
     
     
       27. The image acquisition and processing device of claim 26, wherein said scan end judgment device determines the scan end event to occur at a time period immediately prior to detection of a black region at a periphery of either sensor read area, even when subsequent temporal changes to either image data stream has been detected. 
     
     
       28. The image acquisition and processing device of claim 25, wherein said scan start speed judgment device estimates a scanning speed at the scan end event based on an overall scanning speed calculated by said overall speed judgment device immediately before the scan start event and the input image after the scan end event. 
     
     
       29. The image acquisition and processing device of claim 28, wherein said scan end speed judgment devices assumes the scanning speed at the scan end event to be zero when a black region is perceived in the input image after the scan end event which does not extend to a periphery of either sensor read area. 
     
     
       30. The image acquisition and processing device of claim 28, wherein said scan end speed judgment device estimates the scanning speed at the scan end event based on an overall scanning speed calculated by said overall speed judgment device immediately before the scan end event when the input image after the scan end event is either entirely white or contains a black region extending to a periphery of either sensor read area. 
     
     
       31. The image acquisition and processing device of claim 30, wherein said scan end speed judgment device assumes the scanning speed at the scan end event to be zero when the estimated scanning speed at the scan end event is less than zero. 
     
     
       32. An image acquisition and processing device, comprising: an image input member for acquiring character and graphical information from a document, said image input member comprising: a scan activation means for selectively activating and deactivating scanning operations within said image input member; and   spaced apart first and second sensors for reading the character and graphical information when illuminated by a light source and converting the read-in information into corresponding first and second image data streams in response to said scan activation means; and     an image processing member in communication with said image input member, said image processing member comprising: a buffer in communication with said image input member for receiving and storing the first and second image data streams;   an overall speed judgment device in communication with said buffer for extracting image features for the first and second image data streams, comparing the extracted features for the first and second image data streams and obtaining correlation and time-offset information therefrom, and generating overall scanning speed in response to the obtained correlation and time-offset information;   a scan start judgment device in communication with said buffer for detecting when said image input member has commenced scanning movement with said scan activation means activating scan operations, and generating a scan start event if scanning movement has been so detected; and   a scan start speed judgment device in communication with said scan start judgment device, said overall speed judgment device for generating a scanning speed at the scan start event generated by said scan start judgment device; and   an image corrector in communication with said overall speed judgment device and said scan start speed judgment device for correcting scanning distortion present in one of the stored image data streams based on the scanning speeds generated by said scan start speed judgment and overall speed judgment devices.     
     
     
       33. The image acquisition and processing device of claim 32, wherein said scan start judgment device observes temporal changes in the first and second image data streams and determines that a scan start event has occurred when there is a change in either image data stream. 
     
     
       34. The image acquisition and processing device of claim 33, wherein said scan start judgment device observes temporal changes in the first and second image data streams and determines that a scan start event has not occurred when a black region is perceived within a periphery of either sensor read area when a change has been detected within either of the image data streams. 
     
     
       35. The image acquisition and processing device of claim 33, wherein said scan start speed judgment device estimates a scanning speed at the scan start event based on an overall scanning speed calculated by said overall speed judgment device immediately after the scan start event and the input image prior to the scan start event. 
     
     
       36. The image acquisition and processing device of claim 35, wherein said scan start speed judgment devices assumes the scanning speed at the scan start event to be zero when a black region is perceived in the input image prior to the scan start event which does not extend to a periphery of either sensor read area. 
     
     
       37. The image acquisition and processing device of claim 35, wherein said scan start speed judgment device estimates the scanning speed at the scan start event based on an overall scanning speed calculated by said overall speed judgment device immediately after the scan start event when the input image prior to the scan start event is either entirely white or contains a black region extending to a periphery of either sensor read area. 
     
     
       38. The image acquisition and processing device of claim 37, wherein said scan start speed judgment device assumes the scanning speed at the scan start event to be zero when the estimated scanning speed at the scan start event is less than zero. 
     
     
       39. The image acquisition and processing device of claim 32, wherein said buffer comprises a ring buffer; and   wherein said image processing member further comprises a ring buffer write end position update device in communication with said scan start event device and said ring buffer for manipulating a write end address of said ring buffer when image data from either said first and second image data streams is deposited in said ring buffer and continually updating the write end address until a scan start event has been generated by said scan start judgment device.   
     
     
       40. The image acquisition and processing device of claim 32, said image processing member further comprising: a scan end judgment device in communication with said buffer for detecting when said image input member has terminated scanning movement with said scan activation means activating scan operations, and generating a scan end event if no scanning movement has been so detected; and   a scan end speed judgment device in communication with said scan end judgment device, said overall speed judgment device, and said image corrector for generating a scanning speed at the scan end event generated by said scan end judgment device; and   wherein said image corrector corrects scanning distortion present in one of the stored image data streams based on the scanning speeds generated by said pre/post stop state speed judgment, said scan end speed judgment, and said overall speed judgment devices.   
     
     
       41. The image acquisition and processing device of claim 40 wherein said scan end judgment device observes temporal changes in at least one of said image data streams and determines that said image input member is in the scan end state when no temporal changes have been detected for at least a second predetermined time period. 
     
     
       42. The image acquisition and processing device of claim 41, wherein said scan end judgment device determines the scan end event to occur at a time period immediately prior to detection of a black region at a periphery of either sensor read area, even when subsequent temporal changes to either image data stream has been detected. 
     
     
       43. The image acquisition and processing device of claim 40, wherein said scan start speed judgment device estimates a scanning speed at the scan end event based on an overall scanning speed calculated by said overall speed judgment device immediately before the scan start event and the input image after the scan end event. 
     
     
       44. The image acquisition and processing device of claim 43, wherein said scan end speed judgment devices assumes the scanning speed at the scan end event to be zero when a black region is perceived in the input image after the scan end event which does not extend to a periphery of either sensor read area. 
     
     
       45. The image acquisition and processing device of claim 43, wherein said scan end speed judgment device estimates the scanning speed at the scan end event based on an overall scanning speed calculated by said overall speed judgment device immediately before the scan end event when the input image after the scan end event is either entirely white or contains a black region extending to a periphery of either sensor read area. 
     
     
       46. The image acquisition and processing device of claim 45, wherein said scan end speed judgment device assumes the scanning speed at the scan end event to be zero when the estimated scanning speed at the scan end event is less than zero. 
     
     
       47. An image acquisition and processing device, comprising: an image input member for acquiring character and graphical information from a document, said image input member comprising: a scan activation means for selectively activating and deactivating scanning operations within said image input member; and   spaced apart first and second sensors for reading the character and graphical information when illuminated by a light source and converting the read-in information into corresponding first and second image data streams in response to said scan activation means; and     an image processing member in communication with said image input member, said image processing member comprising: a buffer in communication with said image input member for receiving and storing the first and second image data streams;   an overall speed judgment device in communication with said buffer for extracting image features for the first and second image data streams, comparing the extracted features for the first and second image data streams and obtaining correlation and time-offset information therefrom, and generating overall scanning speed in response to the obtained correlation and time-offset information;   a scan end judgment device in communication with said buffer for detecting when said image input member has terminated scanning movement with said scan activation means activating scan operations, and generating a scan end event if no scanning movement has been so detected; and   a scan end speed judgment device in communication with said scan end judgment device and said overall speed judgment device for generating a scanning speed at the scan end event generated by said scan end judgment device; and   an image corrector in communication with said overall speed judgment device and said scan end speed judgment device for correcting scanning distortion present in one of the stored image data streams based on the scanning speeds generated by said scan end speed judgment and overall speed judgment devices.     
     
     
       48. The image acquisition and processing device of claim 47 wherein said scan end judgment device observes temporal changes in at least one of said image data streams and determines that said image input member is in the scan end state when no temporal changes have been detected for at least a second predetermined time period. 
     
     
       49. The image acquisition and processing device of claim 48, wherein said scan end judgment device determines the scan end event to occur at a time period immediately prior to detection of a black region at a periphery of either sensor read area, even when subsequent temporal changes to either image data stream has been detected. 
     
     
       50. The image acquisition and processing device of claim 47, wherein said scan start speed judgment device estimates a scanning speed at the scan end event based on an overall scanning speed calculated by said overall speed judgment device immediately before the scan start event and the input image after the scan end event. 
     
     
       51. The image acquisition and processing device of claim 50, wherein said scan end speed judgment device assumes the scanning speed at the scan end event to be zero when a black region is perceived in the input image after the scan end event which does not extend to a periphery of either sensor read area. 
     
     
       52. The image acquisition and processing device of claim 50, wherein said scan end speed judgment device estimates the scanning speed at the scan end event based on an overall scanning speed calculated by said overall speed judgment device immediately before the scan end event when the input image after the scan end event is either entirely white or contains a black region extending to a periphery of either sensor read area. 
     
     
       53. The image acquisition and processing device of claim 52, wherein said scan end speed judgment device assumes the scanning speed at the scan end event to be zero when the estimated scanning speed at the scan end event is less than zero. 
     
     
       54. A method for acquiring and processing images presented on a document, comprising the steps of: (A) scanning at least one document image into a plurality of image data streams when a scan activation button of an image input member is depressed;   (B) storing the image data streams into a buffer;   (C) extracting image features form the stored image data streams;   (D) comparing the extracted image features of the stored image data streams;   (E) obtaining correlation and time-offset information based on the extracted image features compared in said comparing step (D);   (F) calculating an overall scanning speed based on the correlation and time-offset information obtained in said obtaining step (E);   (G) detecting a scan stop event based on the stored image data streams when the scan activation button of the image input member is depressed;   (H) determining a scan stop time interval if the scan stop is detected in said detecting step (G);   (I) estimating scanning speeds immediately before and after the scan stop time interval determined in said determining step (H), based on the overall scanning speed calculated in said calculating step (F), when the scan stop event is detected in said detecting step (G);   (J) detecting a scan start event based on the stored image data streams when the scan activation button of the image input member is depressed;   (K) estimating a scanning speed at the scan start event based on the overall scanning speed calculated in said calculating step (F) when the scan start event in detected in said detecting step (J);   (L) detecting a scan end event when the image input member has terminated scanning movement with the scan activation button released;   (M) estimating a scanning speed at the scan end event based on the overall scanning speed calculated in said calculating step (F) when the scan end event is detected in said detecting step (L); and   (N) correcting scanning distortion present in one of the stored image data streams based on the scanning speeds estimated in said estimating steps (I), (K), and (M) and the overall scanning speed calculated in said calculating step (F).   
     
     
       55. An article of manufacture, comprising a computer usable medium having readable code means embodied therein for processing a plurality of image data streams developed through scanning a document by an input image member having a scan activation button, the computer readable program code means comprising: (A) computer readable program code means for storing the image data streams into a buffer;   (B) computer readable program code means for extracting image features form the stored image data streams;   (C) computer readable program code means for comparing the extracted image features of the stored image data streams;   (D) computer readable program code means for obtaining correlation and time-offset information based on the extracted image features compared in said comparing means (C);   (E) computer readable program code means for calculating an overall scanning speed based on the correlation and time-offset information obtained in said obtaining means (D);   (F) computer readable program code means for detecting a scan stop event based on the stored image data streams when the scan activation button of the image input member is depressed;   (G) computer readable program code means for determining a scan stop time interval if the scan stop is detected in said detecting means (F);   (H) computer readable program code means for estimating scanning speeds immediately before and after the scan stop time interval determined in said determining means (G), based on the overall scanning speed calculated in said calculating means (E), when the scan stop event is detected in said detecting means (F);   (I) computer readable program code means for detecting a scan start event based on the stored image data streams when the scan activation button of the image input member is depressed;   (J) computer readable program code means for estimating a scanning speed at the scan start event based on the overall scanning speed calculated in said calculating means (E) when the scan start event in detected in said detecting means (I);   (K) computer readable program code means for detecting a scan end event when the image input member has terminated scanning movement with the scan activation button released;   (L) computer readable program code means for estimating a scanning speed at the scan end event based on the overall scanning speed calculated in said calculating means (E) when the scan end event is detected in said detecting means (K); and   (M) computer readable program code means for correcting scanning distortion present in one of the stored image data streams based on the scanning speeds estimated in said estimating means (H), (J), and (L) and the overall scanning speed calculated in said calculating means (E).